smartstarter

Remote start, lock, and unlock your car from anywhere

Overview

The SmartStarter is a device that lives in your car and allows you to unlock, lock, or remote start that car via text message. Each option is just an SMS away. No more waiting for the car to warm up while you freeze!

My Solution

Remote start the car via text! I combined an Arduino, a 3G modem, a spare car remote, and a handful of components to create a device that can remotely start (and lock/unlock) my car anywhere there is 3G cellphone service.

The Problem

Sitting in your car and freezing while you wait for the car to warm up sucks. My car has remote start capability, but the range is limited to about a block. I often park 3 or 4 blocks away from my apartment, which renders the remote starter useless.

design & fabrication

For v1 prototype, I used an Arduino Uno and wired everything together on a breadboard. The device worked, but was not reliable, as it quickly drained the LiPo battery and required regular recharging. Full write up of v1 here.

For v2, I switched to an Arduino Pro Mini for power savings, migrated the circuit to a perf board, moved the device into a project box, and hardwired the SmartStarter to a 12v line in my car. Powering the device off the 12v allowed for greater reliability, but at the cost of a constant 60mA drain of my car battery. Full write up of v2 here.

For v3, I improved the circuit design and code, increasing the power savings and reliability of the device. I cut a custom PCB for the device and migrated all the circuit to the board. The device now goes into deep sleep mode (consuming under 5mA) for 5 minute intervals, waking briefly to check for incoming texts and perform a task. A secondary line in directly from the car battery is pulled through a voltage divider to check the status of the car battery. If the car battery is low, the device sends a text to me to run the car and switches to 1 hour deep sleep intervals. Finally, I added state detection to the lock, unlock, and remote start functions — the device now provides accurate feedback as to whether or not the requested action was completed successfully, texting me after the fact. Full write up of v3 coming soon.